Molten metal ladle

ABSTRACT

An object of the present invention is to provide a molten metal ladle in which scales, slag, etc., that adhere to the lining surface can be removed easily and reliably. 
     The present invention provides a molten metal ladle provided with a bottomed tubular ladle body having an opening on the top, wherein the ladle body ( 10 ) has an upper ladle portion ( 12 ) and a lower ladle portion ( 11 ); the upper ladle portion ( 12 ) being connected to the top end of the lower ladle portion ( 11 ); lining layers ( 17,18 ) being provided inside the upper ladle portion ( 12 ) and lower ladle portion ( 11 ); and the innermost surface of the lining layer ( 18 ) of the upper ladle portion ( 12 ) being formed as an inclined plane wherein the opening area decreases from the top of the lining layer ( 17 ) of the lower ladle portion ( 11 ) toward the edge of the opening ( 13 ).

TECHNICAL FIELD

The present invention relates to a molten metal ladle.

BACKGROUND OF THE INVENTION

Heretofore, transportation of aluminum or like molten metal has beenconducted in such a manner that the molten metal is first removed from afurnace and poured into a molten metal ladle in a foundry, and thentransferred to a manufacturing site inside or outside the foundry usinga fork lift, etc. Patent Document 1 discloses an example of such amolten metal ladle.

As shown in FIG. 4, the molten metal ladle 100 disclosed in PatentDocument 1 comprises a ladle body 102 having a molten metal dischargingtube 101, and a lid 104 covering an opening 103 provided on top of theladle body 102. As shown in the figure, the ladle body 102 has across-sectional structure wherein an outer covering 105 formed of asteel plate is provided on the outermost side, and a lining layer 108formed of a heat-insulating member 106 and a refractory member 107 isprovided inside the outer covering 105.

When the molten metal ladle 100 is repeatedly used to transport moltenmetal, scales, slag and the like adhere to the innermost surface of thelining layer 108 in the ladle body 102. If the scales, slag and the likethat adhere to the innermost surface of the lining layer 108 fall intothe molten metal, problems occur, such as a lowering of the purity ofthe molten metal. Therefore, the scales, slag, etc., have to be removedperiodically or when they adhere. A method wherein scales, slag and thelike are scratched off using a scraper or like tool is employed as ameans for removing the scales, slag and the like adhered to theinnermost surface of the lining layer 108.

[Patent Document 1] Japanese Unexamined Patent Publication No.2000-106935

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, it is difficult to clean the lining layer 108 disposed in theladle body of the molten metal ladle of Patent Document 1. Specifically,because the innermost surface 108 b of the upper portion lining layer108 a provided on the inner surface of the top end 102 a of the ladlebody 102 is horizontal, the operator has to put his or her head into theopening 103 or use a mirror to check the adhesion and removal of thescales, slag, etc., to or from the innermost surface 108 b. This makeschecking adhesion and/or removal of the scales, slag, etc., troublesome.Furthermore, when the innermost surface 108 b of the upper portionlining layer 108 a or area near the upper corner 109 of the lining layer108 is cleaned, the edge of the opening 103 interferes with the scraperor like removing tool. This adversely affects the cleaning and removingoperation and makes complete removal of scales, slag, etc., difficult.

An object of the present invention is to solve the above problem andprovide a molten metal ladle in which scales, slag and the like thatadhere to the lining layer can be easily and reliably removed.

Means for Solving the Problem

The object of the present invention can be achieved by a molten metalladle comprising a bottomed tubular ladle body having an opening in thetop, wherein the ladle body has an upper ladle portion and a lower ladleportion, the upper ladle portion being connected to the top end of thelower ladle portion, a lining layer being provided inside the upperladle portion and the lower ladle portion, and the innermost surface ofthe lining layer in the upper ladle portion being formed as an inclinedplane with its opening area becoming smaller from the top end of thelining layer of the lower ladle portion toward the edge of the opening.

In this molten metal ladle, it is preferable that the inclined planehave a fixed inclination angle from the top end of the lining layer ofthe lower ladle portion to the edge of the opening as seen in a verticalsectional view.

It is also preferable that the lining layer be formed of aheat-insulating member and a refractory member.

EFFECT OF THE INVENTION

The present invention provides a molten metal ladle in which scales,slag, etc., that adhere to the surface of the lining layer can be easilyand reliably removed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1( a) shows a cross-sectional view of a molten metal ladleaccording to one embodiment of the present invention, and FIG. 1 (b)shows a cross-sectional view of FIG. 1( a) taken along the line A-A.

FIG. 2 is a cross-sectional view of a molten metal ladle according toanother embodiment of the present invention.

FIG. 3 is a cross-sectional view of a molten metal ladle according tostill another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a known molten metal ladle.

EXPLANATION OF REFERENCE NUMERALS

-   -   1 molten metal ladle    -   10 ladle body    -   11 lower ladle portion    -   12 upper ladle portion    -   13 opening    -   14 outer covering    -   15 heat-insulating member    -   16 refractory member    -   17 lower portion lining layer    -   17 a innermost surface    -   18 upper portion lining layer    -   18 a innermost surface    -   19 lid lining layer    -   20 connecting portion    -   30 molten metal discharging tube    -   31 pressurizing member    -   32 lid    -   33 foot    -   33 a fork pockets

BEST MODE FOR CARRYING OUT THE INVENTION

The molten metal ladle of the present invention is explained in detailbelow with reference to the attached drawings. FIG. 1( a) is across-sectional view of a molten metal ladle according to one embodimentof the present invention and FIG. 1 (b) is a cross-sectional view ofFIG. 1( a) taken along the line A-A.

As shown in FIG. 1, the molten metal ladle 1 is a ladle from whichmolten metal is discharged by the application of pressure. The moltenmetal ladle 1 comprises a ladle body 10, a molten metal discharging tube30, a pressurizing member 31, a lid 32, and a pair of feet 33,33.

The ladle body 10 has a tubular form with a circular shape as seen in ahorizontal sectional view, and comprises a lower ladle portion 11 and anupper ladle portion 12. The lower ladle portion 11 is a bottomedcylinder having a constant outer diameter, and its upper end is incontact with the upper ladle portion 12. On top of the upper ladleportion 12, an opening 13 having a diameter smaller than the insidediameter of the bottom surface of the lower ladle portion 11 is formed.The upper ladle portion 12 has a tapered external form, i.e., itshorizontal sectional area becomes smaller from the top of the lowerladle portion 11 toward the upper portion. Note that, the lower ladleportion 11 and the upper ladle portion 12 may be formed in a unitedmanner or formed independently and then connected using a connectingmember.

The cross-sectional structure of the lower ladle portion 11 is such thatan outer covering 14 formed of a steel plate is provided on the outside,and a lower portion lining layer 17 formed of a heat-insulating member15 and a refractory member 16 and having a shape similar to the outercovering 14 is provided along the outer covering 14. The upper ladleportion 12 has the same cross-sectional structure as the same as that ofthe lower ladle portion 11, wherein an outer covering 14 formed of asteel plate is provided on the outside, and an upper portion lininglayer 18 formed of a heat-insulating member 15 and a refractory member16 and having a shape similar to the outer covering 14 is formed on theinside of the outer covering 14. The innermost surface 18 a of the upperportion lining layer 18 is formed as an inclined plane wherein theopening area becomes smaller from the top of the innermost surface 17 aof the lower portion lining layer 17 toward the edge of the opening 13.This inclined plane is formed so as to have a fixed inclination anglefrom the upper end of the innermost surface 17 a of the lower portionlining layer 17 toward the edge of the opening 13 in the longitudinalsectional view of FIG. 1.

Here, insulating firebricks, ceramic fiber felt, mortar, etc., can beused as materials for the heat-insulating member 15. Refractory bricks,castable refractory, plastic refractory, etc., can be used as materialsfor the refractory member 16.

One end 30 a of the molten metal discharging tube 30 is open to theinside of the ladle body 10 in the vicinity of the bottom surface, andthe other end 30 b is open to the outside of the ladle body 10.

The pressurizing member 31 projects obliquely upward from the ladle body10, and comprises a compressed air inlet 31 a. A means for supplyingcompressed air (such as a compressor), which is not shown in the figure,is connected to the compressed air inlet 31 a. Teeming is conducted byapplying pressure to the inside of the ladle body 10 using compressedair so that molten metal is discharged from the molten metal dischargingtube 30. Note that the inside the ladle body 10 also may be pressurizedusing a compressed inert gas instead of compressed air.

An openable and closable lid 32 is provided on top of the ladle body 10so as to cover the opening 13 of the ladle body 10. The cross-sectionalstructure of the lid 32 is such that an outer covering 14 formed of asteel plate is provided on the outermost side, and a lid lining layer 19comprising a heat-insulating member 15 and a refractory member 16 isprovided inside the outer covering 14.

A pair of feet 33,33 are provided on the bottom surface of the ladlebody 10 in such a manner that one foot 33 is parallel to the other foot33. A fork pocket 33 a into which the fork portion of a forklift can beinserted is formed in each foot 33, so that molten metal ladle 1 can betransported by a forklift.

A method for cleaning and removing the scales, slage, etc., that adhereto the upper portion lining layer 18 and the lower portion lining layer17 of the molten metal ladle 1 of the above-described structure isexplained below. First, the operator of the removal operation opens thelid 32, and checks the adhesion condition of scales, slag, etc., to theupper portion lining layer 18 and the lower portion lining layer 17,etc., from the opening 13 of the upper portion of the ladle body 10.

Subsequently, scales, slag, etc., that adhere to the upper portionlining layer 18 and the lower portion lining layer 17 are removed usinga scraper or like removing tool.

Specifically, scales, slag, etc., that adhere to the innermost surfaces18 a, 17 a of the upper portion lining layer 18 and the lower portionlining layer 17 a are scratched off by inserting a scraper or likeremoving tool into the ladle body 10 from the opening 13.

Because the innermost surface 18 a of the upper portion lining layer 18in the upper ladle portion 12 is formed as an inclined plane wherein theopening area becomes smaller from the top end of the innermost surface17 a of the lower portion lining layer 17 toward the edge of the opening13, the operator who removes the scales, slag, etc., does not have tocheck the adhesion condition by inserting his or her head into theopening 13 during the removal operation. This allows the operator toreliably remove scales, slag, etc., from outside the opening 13 in acomfortable position while checking the adhesion/removal condition ofall of surfaces 18 a, 17 a of the upper portion lining layer 18 and thelower portion lining layer 17. Furthermore, when the innermost surface18 a of the upper portion lining layer 18 or the area near theconnecting portion 20 between the innermost surface 18 a of the upperportion lining layer 18 and the innermost surface 17 a of the lowerportion lining layer 17 is cleaned, the operator can handle a scraper orlike removing tool without interference from the edge of the opening 13,and this simplifies the removal operation.

Because the innermost surface 18 a of the upper portion lining layer 18in the upper ladle portion 12 is formed as an inclined plane wherein theopening area decreases from the top end of the innermost surface 17 a ofthe lower portion lining layer 17 toward the edge of the opening 13,when molten metal is placed in the lower ladle portion 11, a space isformed between the surface of the molten metal and the inner surface ofthe lid 32. This effectively prevents adhesion of the molten metal tothe inner surface of the lid 32, even if the molten metal splashes inthe ladle body 10 when transporting the molten metal ladle 1 or pouringthe molten metal.

Furthermore, because the innermost surface 18 a of the upper portionlining layer 18, which forms an inclined plane, has a fixed inclinationangle from the top end of the innermost surface 17 a of the lowerportion lining layer 17 toward the edge of the opening 13 as shown inthe cross-sectional view of FIG. 1 (b), adhesion and removal of scales,slag, etc., to or from the innermost surface 18 a can be easily checked.When the scales, slag, etc., that adhere to the innermost surface 18 aof the upper portion lining layer 18 are removed, the operator canremove the scales, slag, etc., without drastically changing the holdingposition of a scraper or like removing tool, and therefore the removaloperation can be conducted quickly.

In the upper ladle portion 12, because the upper portion lining layer 18is provided in such a manner that the innermost surface 18 a of theupper portion lining layer 18 forms an inclined plane wherein theopening area decreases from the top end of the innermost surface 17 a ofthe lower portion lining layer 17 toward the edge of the opening 13, itis possible to effectively prevent dropping of the refractory member 16,such as a refractory brick, that forms the upper portion lining layer18. In other words, because a part of the weight of each refractorymember 16 is supported by a refractory member 16 immediately below, thetensile load in the gravity direction generated in the lining surface ofthe refractory member 16 is reduced, and therefore dropping of therefractory member 16 can be effectively prevented.

Here, it is preferable that the angle θ between the inclined line of theinnermost surface 18 a of the upper portion lining layer 18 and the lineconnecting the connecting portion 20 to the edge of the opening 13 besuch that the scraper will not be caught by the edge of the opening 13when the scales, slag, etc., that adhere to the innermost surface 18 aare removed using a straight scraper as shown in the cross-sectionalview of FIG. 1( b). The inclination angle is preferably, for example, 5°to 30°.

One embodiment of the present invention is described above; however, thescope of the present invention is not limited to this. For example, inthe present embodiment, the upper ladle portion 12 has a taperedexternal form, but the external form of the upper ladle portion 12 isnot limited as long as the innermost surface 18 a of the upper portionlining layer 18 provided inside the upper ladle portion 12 is formed asan inclined plane wherein the opening area decreases from the top end ofthe lower portion lining layer 17 toward the edge of the opening 13, andthe external form may be tubular having a consistent outer diameter inthe height direction.

Furthermore, in the present embodiment, a pressurizing-type molten metalladle is employed as the molten metal ladle 1, wherein teeming isconducted by pressurizing the inside of the ladle body 10 by sendingcompressed air, etc., therein so as to discharge the molten metal storedin the ladle body 10 to the outside. However, it is also possible toemploy a tilting molten metal ladle as shown in FIG. 2 by which moltenmetal can be discharged from the discharging port 51 by tilting themolten metal ladle.

In the present embodiment, the innermost surface 18 a of the upperportion lining layer 18 is formed as an inclined plane having a fixedinclination angle from the top end of the innermost surface 17 a of thelower portion lining layer 17 to the edge of the opening 13 as shown inthe cross-sectional view of FIG. 1( b). However, it is also possible toform the innermost surface 18 a of the upper portion lining layer 18 asan inclined plane having a smooth curve connecting the innermost layer17 a of the lower portion lining layer 17 with the edge of the opening13 as shown in the cross-sectional view of FIG. 3.

1. A molten metal ladle comprising a bottomed tubular ladle body and anopening in an upper portion thereof; the ladle body being provided withan upper ladle portion and a lower ladle portion; the upper ladleportion being connected to the top end of the lower ladle portion; theupper ladle portion and the lower ladle portion each being provided witha lining layer inside thereof; the innermost surface of the lining layerof the upper ladle portion being formed as an inclined plane having anopening area decreasing from the top end of the lining layer of thelower ladle portion to the edge of the opening.
 2. A molten metal ladleaccording to claim 1, wherein the inclined plane has a fixed inclinationangle, as seen in a longitudinal sectional view, from the top end of thelining layer of the lower ladle portion to the edge of the opening.
 3. Amolten metal ladle according to claim 1 or 2, wherein the lining layeris formed of a heat-insulating member and a refractory member.